I gurantee you that 99% of people dont yell, "Wow! There is alot of kinetic energy on this ride." Most people would say "Were going fast!" The roller coaster starts with a bit of KE because its moving and increases the amount of GPE the higher it goes. At point two, there is alot of KE because the GPE turned into KE while going down the steep ramp, and there is no GPE because its height is at 0. Point three is where the car goes up the ramp, so the GPE goes up as it gains height and the KE goes down because it is slowing down. When the roller coaster is at the top of the loop, or point 4, the GPE is not as high as point 1 because there had to be alot of KE going down he ramp to flip, so there is hardly any KE. I believe GPE and KE are connected because GPE has the potential to turn into KE and when KE goes up, GPE goes down.